Genetic influences on autism estimated at between 74-98 per cent

Researchers have found that autism spectrum disorder (ASD) is more heritable than recent studies have suggested with genetic influences on the disorder estimated to fall between 74-98 per cent.

Genetic risk factors for ASD were also found to overlap with the genes that influence less extreme autistic skills and behaviours seen in the general population.

The study was carried out by researchers at the Institute of Psychiatry, Psychology & Neuroscience (IoPPN), King’s College London and published today in JAMA Psychiatry.

‘Our main finding was that the heritability of ASD was high. These results further demonstrate the importance of genetic effects on ASD, despite the dramatic increase in prevalence of the disorder over the last 20 years,’ said lead author Beata Tick from the IoPPN, King’s College London.

‘They also confirm that genetic factors lead to a variety of autistic skills and behaviours across the general population.’

Data came from the population-based Twins Early Development Study (TEDS), funded by the UK Medical Research Council (MRC), and included all twins from the TEDS born in England and Wales between 1994 and 1996. In depth, home-based evaluations were carried out on 258 twins selected from the initial group of over 6,000 twin pairs, using state-of-the-art diagnostic interviews and play-based assessments, and 181 twins from the subgroup were diagnosed with ASD.

Results were consistent across several diagnostic tools and the robust findings could be used as a benchmark for future work in the field.

Professor Patrick Bolton, a senior author also from the IoPPN at King’s, said: ‘The comparison of identical and non-identical twins is a well-established way of clarifying the extent of genetic and environmental influences in autism.

‘The novel aspect of this study was the inclusion of twins regardless of whether they had a clinical diagnosis. This enabled us to get a more accurate picture of how influential a child’s environmental experiences and their genetic makeup is on ASD, as well as on subtler expressions of autistic skills and behaviours.

‘Our findings add weight to the view that ASD represents the extreme manifestation of autistic skills and behaviours seen in the general population.’

Funding for the Twins Early Development Study was by the UK MRC, and the Social Relationship Study was also funded by the MRC. Further support for the study was from the National Institute for Health Research Maudsley Biomedical Research Centre at King’s and the South London and Maudsley NHS Foundation Trust, and an Autism Speaks grant.

Scientists at King’s College London have collected evidence from a population-based sample revealing that genetic factors outweigh more moderate environmental influences regards risk of autism and related traits in personality. They published their results online this week in JAMA Psychiatry.

Over 6,000 twins, born in England and Wales between 1994 and 1996, with a variety of autism-related traits – high and low subclinical levels, as well as ASD, – participated in several evaluations: the Childhood Autism Spectrum Test (6,423 twins), the Development and Well-being Assessment (359), the Autism Diagnostic Observation Schedule (203), the Autism Diagnostic Interview-Revised (205), and a best-estimate diagnosis (207) – and all of them showed consistency in their results. […]

“Our main finding was that the heritability of ASD was high. These results further demonstrate the importance of genetic effects on ASD, despite the dramatic increase in prevalence of the disorder over the last 20 years,” said lead author Beata Tick in a statement.

“They also confirm that genetic factors lead to a variety of autistic skills and behaviors across the general population,” Tick added. […]

Our findings add weight to the view that ASD represents the extreme manifestation of autistic skills and behaviors seen in the general population,” Bolton added.

Thanks to new research, we may be able to see autism in the same way we see a broken ankle on an X-ray. (Photo by Getty Images)

Psychiatric disorders – including autism – are currently diagnosed based on a clinical behavioral assessment, a process that’s highly nuanced and highly subjective.

To assess for autism in toddlers include, parents are asked: “If you point at something across the room, does your child look at it,” and “does your child play pretend or make-believe?” Anyone with a young child knows that these types of general questions are very difficult to conclusively answer.

But now, Carnegie Mellow University researchers have created a potentially decisive way to diagnose autism— and other psychiatric disorders — with 97 percent accuracy: By examining how our brains respond to the thought of a hug.

But that’s the problem with this whole autism business; we want precisely what is not available to us — something definitive, like a cause, a cure. Enough, already, with the ambiguities, the gray zones.

Still, it was definitiveness that was worrying me when I began reading “The Kids Who Beat Autism,” Ruth Padawer’s cover story in the Aug. 3rd New York Times Magazine. Mainly, I didn’t want to discover all the things my wife, Cynthia, and I could have done and didn’t. That thought keeps me up enough nights as it is.

Joel Yanofsky’s reaction to the recent New York Times Magazine article on The Kids Who Beat Autism strikes a chord within me, the familiar angst among parents of autistic children: Could we have done better? Did we miss something that could have helped? What if we didn’t have the time/resources/energy to do ABA (something that did not become widespread until later)? Could our child have been among the approximately 10% who “recover” from autism??

Some people would say that Rob is among that 10%. He is certainly “indistinguishable” from the non-autistic population in casual interaction, but he has some social deficits that become more obvious in extended and/or repeated interactions, and that affect his ability to hold certain types of jobs. Could any of this have been helped if he had been diagnosed earlier, and if he had been given intensive ABA treatment? It is hard to say. We feel fortunate that he is highly functional. But I would not say that he has outgrown, recovered from or “beat” his autism. The ambiguity of the diagnosis makes it difficult to assess his recovery.

Rob was not diagnosed until about two months before his sixth birthday. He was not withdrawn into his own little world so much, as he was hyperactive, aggressive, destructive, obsessive, and socially inept in our world. He was verbal, could make eye contact (although he didn’t like to), and we were more concerned about his aggression and destruction than anything else. We concentrated on intensive sensory integration therapy, and the therapies through his school: speech therapy, physical therapy, social skills training, behavior therapy (although not as intensive as ABA).

Rob still has fine motor issues that are very particular (he is a graphic designer, and can draw using a mouse; but not a pencil or pen; his writing is still pretty illegible, even his printing). His gross motor skills are excellent, and he is very athletic. He is intelligent and highly verbal, but still finds social interaction to be stressful. He tends to go into social or psychological “defense mode” easily, still; but at least it is no longer accompanied by physical defense mode as well. He has had some success in community college. He has had some success in work, along with some failures.

If we had to do it over again we would certainly have tried ABA if he had been diagnosed young enough. I think by age six it may have been too late, however. For Rob, I still think the best thing was the sensory integration therapy, because until those issues were addressed it would have been difficult for him to focus on anything else. But I am not an expert, only a parent who tried to do her best in a highly ambiguous situation.

This is a really interesting idea, and seems as if it would be very appealing.

Researchers believe they have developed a psychological technique that improves the mental wellbeing of children with autism – through an activity that invents tiny characters the kids can then imagine are in their heads helping them out with their thoughts.